Final answer:
When installing gypsum in soffit areas, control joints should be installed at a maximum of 30 feet. This practice accommodates expansion and contraction of building materials and prevents cracking of the gypsum due to movement.
Step-by-step explanation:
When installing gypsum in soffit areas, a control joint should be installed at a maximum of 30 feet. The use of control joints in gypsum board assemblies is vital to accommodate the thermal and moisture expansion and contraction of building materials, as well as for structural movement.
Since gypsum is a material that can crack with excessive movement, the proper placement of control joints is an essential aspect of installation to prevent such issues.
Architects and installers should refer to the specific gypsum board manufacturer guidelines and industry standards, such as those from the Gypsum Association or ASTM International, for precise specifications regarding the placement of control joints.